Use for another family member
Cord blood can be used for the child it was collected from, but also for the child’s siblings. Treatment of some diseases required hematopoietic cells from another person - a donor. In these cases an ideal donor is a healthy, compatible sibling. However, for successful transplantation donor must be compatible with the recipient. The HLA antigens (certain tissue characteristics, present on white blood cells) are compared. With siblings there is a 25% chance of absolute compatibility. When searching for a suitable donor in international registers, often no compatible donor can be found amid millions of donors. The use of a child's cord blood for other members of the family is improbable.
Hematopoietic stem cells transplantation
Many diseases cause the failure of hematopoiesis in bone marrow. This means that the production of red and white blood cells and platelets is stopped. The only way to save the patients is to give them healthy hematopoietic cells. So the transplantation of hematopoietic stem cells is the restoration of blood formation in the bone marrow. If the patient’s own cells are used it is called an autologous transplantation. If the cells come from a different person it’s an allogenic transplantation. The choice between an autologous and allogenic transplantation depends on the disease. Stem cells could be derived from either bone marrow or cord blood. It is possible to obtain so-called peripheral blood stem cells from the bone marrow after being treated with certain growth factors.
With autologous transplantations cells are the patient's own so there is no risk of post-transplantation complications. The advantage of cord blood for an autologous transplantation is that cells are collected at the time of birth and so are young and “clean”; not affected by therapy or the aging process. Cells from bone marrow are isolated from the already ill patient during the disease’s remission. However those cells can contain remains of cancer cells or could be previously damaged by chemotherapy. The amount of autologous transplantations is twice that of allogenic transplantations. Autologous hematopoietic cells are often used in diagnoses where a donor's cells wouldn't be used due to possible post-transplantation complications. This is usually the case if the actual disease is less harmful than transplantation from a donor.
Allogenic transplantations are when the hematopoietic stem cells come from someone else. For allogenic transplantation it is necessary to find a donor compatible in certain tissue types - HLA antigens. First the donor is searched for in the immediate family – there is a 25% chance that a sibling will be HLA-compatible. If the patient has no compatible sibling then the public cord blood registry is searched.